| Propulsion

Towed-Glider Airborne Launch System Cuts Costs and Increases Efficiency and Safety

NASA seeks partners to collaborate in the development of this new approach for putting satellites in space, enabling low-cost launch services.

Putting a satellite into low Earth orbit requires a lot of energy, with ground-launched rockets expending two-thirds of their propellant fighting to get through the atmosphere. Researchers at NASA’s Armstrong Flight Research Center have developed an innovative approach to launching satellites into space from an airborne platform. As with other air-launch approaches, it provides significant flexibility in the location and direction of the launch vehicle. Furthermore, unlike other air-based launch techniques, this system avoids the significant drawbacks related to expensive and complex design/development efforts, difficult maneuvering, risks to crew, and inefficient flight performance.

An unmanned aerial vehicle tows a one-third-scale model of the twin-fuselage glider envisioned for NASA Armstrong’s airborne launch concept. The 27-foot-wingspan towed aircraft was successfully released by the UAV and glided to a perfect landing. (NASA photo)

NASA Armstrong’s approach uses a towed glider — which is inexpensive, reusable, and remotely piloted — with a launch vehicle mounted on the glider’s underbelly to put satellites into orbit efficiently, safely, and cost-effectively. Similar to how a fifth-wheel trailer enables a pickup truck to transport much more weight than it could ever directly carry in its bed, a jet transport can tow and lift a much larger launch vehicle to altitude than it could if it were directly carrying it underneath.

Upon achieving the target altitude of approximately 40,000 feet, the airplane releases the glider-launch vehicle combination and leaves the area. The glider then uses its own rocket motor to adjust its trajectory upward while maintaining its airspeed, eventually releasing the launch vehicle from a high flight-path angle. As the rocket finishes departing the atmosphere — using a small fraction of the pro-pellant required for a ground-based launch — the glider returns to its base, where it can be quickly and easily readied for the next mission.

Poised to revolutionize the commercial launch services market, NASA Armstrong’s launch system allows for payloads to orbit that are 30 to 70 percent greater in mass than equivalent launch vehicles provide, using existing air- and ground-based launch techniques, respectively. It avoids the costs of maintaining and operating launch pads and the cost impact of weather-related obstacles to consistent launch schedules. In addition, ground processing of multiple launch vehicles/pay-loads can be conducted in parallel, eliminating the cost impacts due to cascading schedule delays inherent in serial processing multiple launch missions from the same launch pad. The glider can carry a wide variety of launch vehicles with varying geometries with minimal modifications. In addition, its remotely piloted architecture fully mitigates the risk of having an onboard crew in an aircraft attached (or close) to a potentially explosive rocket.

Most importantly at this stage, the system uses existing technologies, avoiding the expense, risk, and timeframe associated with developing and testing new rocket systems. Researchers have completed several successful tests. Now NASA invites commercial partners with the ability to manufacture or procure their own glider(s) to participate in a three-year effort culminating in a full-scale flight test demonstration, for which NASA will provide the required flight test staff and infrastructure. Such an effort is expected to enable the partner company to rapidly provide low-cost launch services to the market at large.

This work was done by Jerry Budd of Armstrong Flight Research Center. NASA is actively seeking licensees to commercialize this technology. Please contact the NASA Armstrong Technology Transfer Office at 661-276-3368 or by e-mail at This email address is being protected from spambots. You need JavaScript enabled to view it. to initiate licensing discussions. DRC-012-011